Three Turkish soldiers and a police officer were killed in separate incidents Saturday, security sources said, as violence roils the country's mainly Kurdish southeast in recent weeks following the end of a two-year cease-fire.

The soldiers were killed and six more were wounded when militants from the autonomy-seeking Kurdistan Workers Party (PKK) detonated a remote-controlled explosive that hit a military convoy traveling near the town of Bingol, the General Staff said on its website.

The police officer, who was part of a special operations unit, was killed after PKK rebels opened fire near Semdinli, close to the Iraqi border, a security source said.

The PKK, classified by Turkey, the United States and the European Union as a terrorist organization, has struck military targets on a near-daily basis since the government first launched airstrikes on rebel camps in northern Iraq on July 25, breaking a two-year cease-fire in the three-decade conflict.

More than 40 members of the security forces have been killed in attacks and 174 have been wounded, according to the government. Turkish media reports have put the PKK's death toll at more than 200.

The southeast is on tenterhooks this weekend as Saturday marked the 31st anniversary of the start of the conflict. An attack on the army in Semdinli on Aug. 15, 1984, is considered the first in the insurgency that went on to claim more than 40,000 lives, mostly Kurdish.

Turkish officials have said its military campaign is designed to tackle both the PKK and Islamic State militants in neighboring northern Syria. It opened up its air bases to U.S.-led coalition jets targeting Islamic State last month.

The NATO ally has staged three airstrikes against the Islamic State in Syria, a government official said. It has launched more than 400 strikes against the PKK in and out of Turkey, he said.

This had raised suspicions among Kurds that Turkey is more interested in curbing Kurdish militants, who have coordinated with the United States since 2014 in battling the Islamic State in Iraq and Syria.